X-ray tube.



R; H. WAPPL ERB X-RAY TUBE. 'APPIJCAIION FllED 0:0.13. m2.

- Patntpd Sept. 7, 1915.

amvemtoz lgvmbmpoow en ine BEINHOLD H. WAPPLER, OF NEW YORK, N. Y., ASSIGNOR TO WAPPLER ELECTRIC MANUFACTURING COMPANY, INC., OF NEW YORK, N. .Y., A CORPORATION OLE NEW YOP Specification of Letters latent.

X-RAY when I Patented Sept. 7, 1915.

Application filed December 13, 1912. Serial No. 756,651.

York, in the county of New York and State of New York, have invented certain new and useful Improvements in X-Ray Tubes, of which the following is a specification, reference being bad therein to the accompanyin drawings, forming part thereof.

y invention relates to X-ray "or Rontgen ray tubes. Such tubes are commonly .pro-

vided with electrode \stems of reduced diameter integral with'th bulb, and the cathode or negative electrode is commonly disposed within the cathode stem at or near its mouth. As a consequence of the strength of the current commonly used in operating X- ray tubes, and of the proximity of the surrounding glass walls-of the mouth of the stem to the cathode, these walls become heated in the X-ray tubes in general use by the current in its passage from the anode to the cathode, and frequent breakages occur at the juncture of the cathode stem with the bulb due to the weakening at this point resulting from the excessive temperature.

An object of my invention is to obviate this difiiculty and eliminate the heating of the walls about the cathode.

A more particular object is to so direct the current as to prevent it from passing in heating proximity to these walls.

Another object is to reduce to a minimum the deleterious inverse currents which impair the efiiciency of the tube. 7

Another object is to confine the anode stream'or the stream passing from the anode to the cathode and thus confine the cathode stream with a resultant confining of the EL rays within the desired area of operation.

Other objects are simplicity and inexpensiveness of construction, and reliability of oper ation.

Still other'objects and advantages of my invention will appear from the following description.

In carrying out my inventioml provide current-directing means onthe reflecting surface of the anode or target,'which is arranged to direct the current within a do fined area of the cathode.- More specifically the current-directing means consists in a pointed conductor arranged to direct the current at substantially .the center of the cathode. Still more specifically the pointed conductor is bent ,or curved and arranged with its base out of the range of the cathode stream and with its pointed end in the line of the stream and directed at the center of the cathode' My invention also includes other features of construction and arrangements of parts, as will hereinafter more fully appear.

. I shall now describe the embodiment of my invention illustrated in the accompanying drawing, and shall thereafter point out my invention in claims. Y I

In the drawing I have shown a side elevation, partly in section, of an X-ray tube embodying my invention.

The tube, which'is composed of glass, is of the familiar shape, having a substantially spherical bulb 1, and projecting from opposite sides thereof an anode stem 2 and a cathode stem 3 in axial "alineinent. The anode 4:, which is composed of copper or other suitable conductive material, isprovided with a plane reflecting surface or target 5, preferably of tungsten, arranged opposite the cathode 6 and at an angle of substantially. 5 to the axial line of the elec trodes, as is usual. The cathode i3 is concave, of the well known construction, and arranged to focus the cathode stream 11 on the reflecting face or target 5, being disposed substantlally at the mouth of the cathode stem 3.

To direct the current from the anode a to the center of the cathode 6, and thereby prevent it from ssing in heatin proximity t0 the walls a out the neck of t e stem 3, I

employ a current-directing member projecting from the reflecting face of the anode 4. In its illustrated form, this member is a removable curved pointed conductor 7, of copper or other suitable metal, provided with a,

screw-threaded attaching end of reduced diameter which engages in escrow-threaded hole in the reflecting face of the anode on its upper side out of the focal range of the cathode 6. This pointed conductor is curved to bring its pointed or discharge end into the focal line of the cathode and di-.

rooted at the center of thecathode, thereby preventing the dissemination of thecurrent abouts large area of the cathode and the heating of the walls in proximity thereto. This directing of the current from the anode within a defined area oi the oath do int E advantage, in that it cathode stream to a ream, and therei 1,, iieid of operarays which fre- Aiso the dis- 1 unevermesses or Y cathode, which results from the use of the pointed conductor '2, serves to decrease the inverse currents characteristic of X-ray tubes, and tothcreby greatly enhance the efficiency of the tube.

It is obvious that various modifications may be madeciin the construction shown and above particularly described Within the principle and scope of my invention i.- claim:

1. In an X-ray tube, cathode, an anode having a plane reflecting surface, and ourrent-directing means on the reflecting surface arranged. to direct the current Within a defined area of the cathode.

2. In an Xa'ajy tube, a cathode, and an anode having a plane reflecting surface and having a pointed conductor extending from such surface and directed at the cathode.

3. In an X--ray tub-e, an anode having a plane reflecting surface, a cathode arranged to focus the cathode rays upon the reflecting ve surface of the surface of the anode, and a pointed conductor extending from the reflecting surface of the anode and arranged to direct the current at substantia'iiy the center of the cathode.

4:- In an X-ray tube, an anode having a plane reflecting surface, a cathode arranged to focus the cathode upon the reflecting surface of the anode, and a pointed conductor extending from the reflecting surface of the anode with its base outside of the cathode stream upon the reflecting surface and arranged to direct/the current at substantially the center of the cathode.

5. In an X-ray tube, an. anode having a plane reflecting surface arranged at an angle to the axis of the anode, a cathode arranged to focus the cathode rays upon the reflecting surface of the anode, and a pointed conductor extending from the upper portion of the reflecting surface of the anode outside of the range of the cathode stream and bent to bring its pointed end in the line of the cathode stream and directed at substantially the center of the cathode.

6 In an X-ray tube, an anode having a plane reflecting surface, a cathode arranged to focus the cathode rays upon the reflecting surface of the anode, and a removable pointed conductor extending from the reflecting surface of the anode and arranged to direct the current at the cathode.

In testimony whereof I have'afiixcd my signature in presence of two witnesses.

REINHOLD H. \VAPPLER. W'itne'sses:

'RoBnR'r A. Maonnn'r, HUGO F. News. 

